Patent GB-1516209-A (GB)
Title: Air conditioning system
IPC: F24F11/04
Filed: 1975-11-17
Abstract: 1516209 Ventilating CARRIER CORP 17 Nov 1975 [29 Nov 1974 (2)] 47313/75 Heading F4V An air-conditioning system for a building comprises a first air-conditioning unit having a heating coil 26 which supplies conditioned air to terminal plenums 61 at a temperature level which can be varied, and a second air-conditioning unit having a cooling coil 31 which supplies conditioned air to terminal plenums 62 at a substantially constant temperature level. Preferably, the air at a variable temperature level passes to the peripheral regions of the building and the air at a constant temperature level passes to the interior regions of the building. The terminals also include a baffle 66 which separates the plenums 61, 62, an air distribution chamber 70 having openings 69, a central partition 76, a diffuser triangle 77, and bladders 73, 74. The terminals further include a control section comprising a first regulator 85, a second regulator 87 and a thermostat 89. Air from plenum 62 can pass through an opening 93, a filter 91, regulator 85, and line 99 to the bladder 74. Similarly air from plenum 61 may pass through opening 97, filter 95, regulator 87, lines 101 and 103 to the bladder 73. The regulators 85 and 87 are provided to generate a control signal indicative of the pressures in the respective plenum chambers. Thermostat 89 modifies the pressure signals supplied by regulator 85 to bladder 74. A further control in the form of a pneumatic valve 107 is also provided. Valve 107 includes a diaphragm 105 separating the valve into sections 109, 111 with a bias spring 112. A line 113 communicates section 111 with plenum section 62, and a line 115 communicates section 109 with line 99, the line 99 having the same pressure as the bladder 74. A communication between the regulator 87 and the section 111 exists in the form of a line 118. The line 118 is connected to the regulator 87 at a point between a bleed opening 119 and a connection point for the air supplied to the bellow 73 via line. 101. In operation of the system during winter, the peripheral air supplied from plenums 61 is relatively warm, and the air supplied through plenums 62 is relatively cold. On sunny days, the thermostat 89, in conjunction with the regulator 85, operates to reduce the pressure signal supplied to the bladder 74, deflating the bladder, and thereby permitting a greater flow of cold air into the centre of the room. Line 115 relays the signal to section 109 of valve 107, lowering the pressure in section 109 and causing the diaphragm 105 to lift and open line 118. The control signal passing through line 118 to point 119 results in an increase in the magnitude of the pressure signal communicated to the peripheral air control bladder 73. The bladder 73 is thereby inflated, terminating the discharge of warm air into the building. On colder days, the corresponding pressure in section 109 will be higher, until at some predetermined point the diaphragm 105 will be forced downwards, closing off the nozzle 117 of line 118. This permits air to bleed to the atmosphere via orifice 121 to decrease the magnitude of the pressure signal supplied to the bladder 73. The bladder 73 thus deflates and allows warm peripheral air to be supplied to the building. During summer conditions, the peripheral system will be inoperative. In a further embodiment (Fig. 5, not shown), a further control valve is provided in the line 118 (218, Fig. 5). This valve provides an additional controlling communication between a bleed line (237) and a line from plenum 61.